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We first learned about electrochemical
energy conversion devices, or fuel cells for short,
during the FIRST 2006 build season. Jeff, one of our
teammates, had developed a strong interest in fuel cell
technology when we were visiting Cleveland for the FIRST
Buckeye Regional Competition. Diane Sadowski, president
of firstfuelcells.com, was giving a presentation about
fuel cells, and it sparked Jeff’s interest. He suggested
we pursue the idea of obtaining and working with a fuel
cell to power our Vex robot, so we decided to go for it.
The fuel cell works by combining
hydrogen and oxygen in the cells to produce water, heat,
and energy. Specifically, the hydrogen passes through a
tube to a valve that measures the amount of hydrogen
passing through. The hydrogen is then forced through the
cell from the cathode, or positive, side, while reacting
with the oxygen that is entering through holes in the
side of the cell. When the oxygen and hydrogen react,
they form water vapor, a harmless byproduct. The
electrons are not allowed to pass through the catalyst,
or electron separation device, and so are rerouted to
the mechanism that the cell is powering. The process
repeats itself, so as to maintain the constant energy
flow.
Last fall, we received the fuel cell in
pieces, which consisted of two polycarbonate end plates,
about twenty cells, cathodes, anodes, catalysts,
separators, and some basic instructions. During assembly
we had to be painstakingly careful not to damage the
parts in any way, which meant we weren’t allowed to
touch most of the pieces except with gloves, and not
even then for others. After we assembled the fuel cell,
we began working constantly with it. This experience has
been great to be a part of, and has been very
educational for us.
We spent many nights testing and
experimenting with ideas on how to produce maximum power
with minimum effort from our fuel cell. When we first
built the fuel cell, we used ten of the twenty initial
cells in the stack. It soon became apparent that this
was not enough to power four motors for a Vex robot, so
we increased the number to fourteen. When the number of
cells was raised, we had more energy, but still not
enough to power four motors, so we placed a fan by the
cell to increase oxygen intake. When this was done, the
four motors ran with energy to spare. We also tried
using a heat gun with the fan to make the fuel cell more
efficient, and it worked very well, but we quickly
learned that the heat gun and the fan were NOT
compatible, because the heat melted the fan. We are
still trying to determine which fan will be the most
efficient, and are currently considering the idea of
using two fans, one to push the oxygen into the cell,
and one to pull the oxygen through the cell to the other
side.
The fuel cell team is continuing testing
to find the most effective way to power the fuel cell.
Once we are done, we will take the fuel cell to
Discovery World to provide educational programs about
how fuel cells work. Fuel cells aren’t just being used
on robots. Fuel cell automobiles are being tested, and
are hoped to be on the market as affordable and
practical alternatives to gasoline powered automobiles
by 2020. Our team found this experience quite enriching,
and is eager to participate in the effort to find
cleaner and more efficient energy alternatives. |
